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Abstract —The fluorescence of housefly photoreceptors was studied in vivo by using the deep pseudopupil technique. Whereas the rhodopsin R490 of the peripheral retinular cells fluoresces negligibly the metarhodopsin M580 fluoresces distinctly in the red. The newly discovered metarhodopsin M'is produced by intense blue light and can be reconverted into rhodopsin by intense long wavelength light. M'also fluoresces in the red; its excitation spectrum and emission spectrum peak at max = 570 and 660 nm respectively.
Intense ultraviolet light irreversibly reduces the visual pigment fluorescence as well as the broad band autofluorescence (kmnx 470 nm) originating from non-visual pigments in the fly's eye. 相似文献
Intense ultraviolet light irreversibly reduces the visual pigment fluorescence as well as the broad band autofluorescence (kmnx 470 nm) originating from non-visual pigments in the fly's eye. 相似文献
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Weydert C. Frixione S. Herquet M. Klasen M. Laenen E. Plehn T. Stavenga G. White C. D. 《The European Physical Journal C - Particles and Fields》2010,67(3-4):617-636
The European Physical Journal C - We discuss the calculation of charged Higgs boson production in association with a top quark in the MC@NLO framework for combining NLO matrix elements with a... 相似文献
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This article reviews recent advances of studies on the spectral organization of the compound eye in lepidopteran and hymenopteran insects. The compound eyes consist of ommatidia, which contain a set of photoreceptor cells. The common feature is that the ommatidia can be divided into three types, according to the combination of spectral classes of photoreceptors. Honeybees and nymphalid butterflies provide the simplest case with three photoreceptor classes having peak sensitivities in the ultraviolet (UV), blue (B), or green (G) wavelength region. These receptors populate the ommatidia in fixed combinations. In type I ommatidia, the main eight photoreceptors consist of one UV, one B, and six G receptors. Type II has two UV and six G receptors, and type III has two B and six G receptors. The organization is basically retained in all insect species studied so far, although some butterflies have more than six classes of spectral receptors, including those sensitive in the violet and red wavelength regions. To acquire these additional receptors, two distinct strategies are applied: the multiple opsin strategy, taken by the Japanese yellow swallowtail butterfly Papilio xuthus, and the filter strategy, used by the small white butterfly Pieris rapae. 相似文献
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Walter T. Giele Gerben C. Stavenga Jan Winter 《The European Physical Journal C - Particles and Fields》2011,71(7):1-13
We have implemented the leading-color n-gluon amplitudes using the Berends–Giele recursion relations on a multi-threaded GPU. Speed-up factors between 150 and 300 are obtained compared to the CPU-based implementation of the same event generator. In this first paper, we study the feasibility of a GPU-based event generator with an emphasis on the constraints imposed by the hardware. Some studies of Monte Carlo convergence and accuracy are presented for PP→2,…,10 jet observables using of the order of 1011 events. 相似文献
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DERIVATION OF PHOTOCHROME ABSORPTION SPECTRA FROM ABSORBANCE DIFFERENCE MEASUREMENTS 总被引:3,自引:0,他引:3
D. G. Stavenga 《Photochemistry and photobiology》1975,21(2):105-110
Abstract— A method is presented with the aid of which the absorption spectrum of at least one of the two states of a photochrome can be calculated from experimental difference spectra. It is shown that the method can be applied to (biological) photochromes contained in inhomogeneous media together with absorbing, non-photochromic impurities. This medium may have the properties of an optical waveguide. 相似文献
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Abstract— The main visual pigment of blowflies (xanthopsin, Vogt, 1983 Z. Naturforsch. 38c ,329–333) photoconverts into two thermostable metaxanthopsin states M and M'(e.g. Stavenga et al. , 1984 Photochem. Photobiol. 40 ,653–659). The fluorescence spectra of the two photoproducts were studied by microspectrofluorometry in vivo. The emission spectra of M and M'are very similar and peak at 660 nm. The excitation spectra of M and M'have peak wavelengths at Λmax ' 584 nm and = 568 nm respectively. 相似文献
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We study corrections suppressed by one power of the soft gluon energy to the resummation of threshold logarithms for the Drell–Yan cross section and for Deep Inelastic structure functions. While no general factorization theorem is known for these next-to-eikonal (NE) corrections, it is conjectured that at least a subset will exponentiate, along with the logarithms arising at leading power. Here we develop some general tools to study NE logarithms, and we construct an ansatz for threshold resummation that includes various sources of NE corrections, implementing in this context the improved collinear evolution recently proposed by Dokshitzer, Marchesini and Salam (DMS). We compare our ansatz to existing exact results at two and three loops, finding evidence for the exponentiation of leading NE logarithms and confirming the predictivity of DMS evolution. 相似文献
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